1. Field of the Invention
The present invention relates to a large display apparatus that receives millimeter waves or terahertz waves from a mobile communication terminal under non-line-of-sight (NLOS) conditions, and more particularly, to a plurality of diversity boards of the large display apparatus that displays massive data seamlessly using millimeter or terahertz communication.
2. Description of the Prior Art
A technology that directly connects a smart phone to a display for demonstration or presentation has been developed. A technology for massive and high-speed communication could be based on a millimeter wave or terahertz wave wireless communication.
Millimeter waves or terahertz waves travel in straight lines and thus, may be used for line-of-sight (LOS) communication. For a non-line-of-sight (NLOS) communication condition, beam-forming technology is generally utilized. Since the beam-forming technology consumes a large amount of power by using a plurality of transceivers, and increases the size of a product, it is difficult to be embodied in a mobile communication terminal such as a smart phone. There is required for a technology that enables communication in an NLOS communication environment in which hindrance occurs when millimeter waves or terahertz waves are used to transmit massive data at high-speed through a mobile communication terminal such as a smart phone.
A transceiver to which a beam-forming technology is applied according to the conventional art configures a transmitter and a receiver in an array structure and provides various RF paths. A phase of each wave is controlled and the wave arrives at the receiver by avoiding an obstacle.
The beam-forming technology illustrated in FIG. 1 provides various paths using an array of antennas and transceivers. Therefore the beam-forming technology may increase a size of a product.
The receiver based on the beam-forming scheme of FIG. 1 has various paths for millimeter waves, and includes a delay device having a different delay time for each path so as to change a phase of each signal. The receiver embodied as an array performs reception by changing an antenna beam pattern in various directions, so as to perform millimeter wave communication by avoiding a bather during transmission and reception.
To embody the beam-forming technology, multiple signal paths are basically required and thus, a large amount of power is consumed and a size of a transceiver is also large. When N paths exist, an amount of power consumption N times greater than an amount of power consumption of a general transmitter or receiver (a transmitter or receiver including a single path) may occur, and a size of a product increases in proportion to a number of arrays.
Korean published patent No. 2012-0030200 discloses a method and apparatus for transmitting data using multiple antennas and beam-forming, which supports a predetermined beam-width regardless of an emission angle and prevents power loss caused by spreading of an angle, but has difficulty in decreasing a size by including an antenna array in a transmitting terminal.